Telephone-switch.



No. 820,432. Y PATENTED MAY 15, 1906. W. E. MoOORMIGK.

TELEPHONE SWITCH,

APPLI UATION TILED AUG. 26, 1901.

2i JP2727/65272 UNITED STATES WILLIAM E. MCCORMICK,

NATIONAL TELEPHONE PATENT OFFICE.

ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE-SWITCH.

Specification of Letters Patent.

Patented May 15, 1906.

Application filed Au ustus, 1901. Serial No. 73,362.

To CLZZ whom it may concern.

Be it known that I, WILLIAM E. McCon- MICK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in TelephoneSwitches, of Which the following is a full, clear, and exact description, which will enable others to make and use the same.

My invention is directed particularly to that type of telephone-switches in which the manipulation of the telephone-receiver effects the necessary circuit changes from the bell-circuit to and through the receiver-circuit, and vice versa.

The principal object of my invention is to simplify the organization of the parts employed in this class of devices, whereby all of the elements and constituent parts of an ordinary telephone hook-switch operating by the removal and replacement of the telephone-receiver are grouped together in a single unitary structure capable of bodily removal and replacement in the ordinary telephone-box and wherein when the ordinary receiver is in position on the switch-hook the switch will be held in such position as to include the associated local signal devices in the line-circuit and when the receiver is re moved from the hook for the purpose of carrying on conversation the switch is automatically moved to cut out the signaling device itnd include the telephone instruments in the Other objects of my invention are directed to certain improvements in the details of construction and arrangement of various parts which may be employed in apparatus of this character.

To these ends my invention consists in the constructions and arrangements substantially as hereinafter more particularly pointed out.

My invention will be fully understood by reference to the accompanying drawings, in which Figure 1 is a side elevation of an organization of parts constituting a mechanical switch embodying my invention. Fig. 2 is a detail side elevation of certain of the parts shown in Fig. 1 and illustrating the arrangement of the contact pieces or terminals employed in the exemplification of my invention. Fig. 3 is a top plan view of the parts shown in Fig. 1.

Fig. 4 is a section on the line 4 4 of Fig. 1.

Fig. 5 is a part diagrammatic and a part elevational view of the circuits, circuit connections, and associated mechanical parts arranged to exemplify a practical application of my invention; and Fig. 6 is a top plan view in detail of one of the switch-terminals removed from its supporting-base.

It is well understood that in operating ordinary telephone-lines it is desired to have the circuit so arranged that the signal device at the subscribers station is normally included in the line-circuit, while the telephone instruments at that subscribers station are excluded therefrom, so that the resistance of the telephone instruments is normally out of the line-circuit, and the instruments themselves are less liable to injury from foreign currents. When the instruments are to be used for conversational purposes, it is desirable to have the local signal devices excluded from the line-circuit, so as to cut out their resistances and to include the telephone instruments. My invention contemplates the accomplishment of these ends by a simple and unitary form of switch operated by the removal and replacement of the telephone-receiver from its switch-arm or hook-switch.

In the drawings the reference-letter A represents a base provided with screw-holes a, by which it is adapted to be secured in place in the ordinary telephone-box, it being understood that it'may be mounted therein in any suitable manner. The base is preferably composed. of a metal plate of anysuitable size and shape adapted for the purpose in view, and in the form illustrated in the drawings it is composed of an upright body fashioned like a box open at its ends and on one side with an integral standard a rising from one edge of its top and to which the switch-hook B is pivoted by a suitable screw-bolt b, the hook extending through a suitable opening in the box in the usual manner and provided at its outer end with the usual yoke b to receive the telephone-receiver. The base A provides a seat in its angular or box-like portion for a block C of suitable insulating material, which is provided in its outer or free side with a se ries of laterally-opening kerfs or slits extending the width thereof and adapted to receive I05 the switch-terminals, designated by the ref- I erence-letters t, t, t and t the arrangement and organization of these several parts being preferably as shown in Fig. 4.

The terminals are preferably in the form of flat leaf-springs and are provided with laterally-extending lugs or ears t and F, as shown in Fig. 6, which embrace the body of the block C and rest against the ends thereof, as shown in Fig. 3, whereby the terminals are held against movement in the kerfs. The open side of the kerfs or slits is closed by an insulating-strip a which retains the terminals in the slits, and the open side of the boX is provided with a closing-piece cf, the several parts being assembled together and held in relative position by a suitable screw-bolt a in the manner shown in Fig. 4. The rear ends of the terminals extend beyond the support or base and are provided with suitable means, as at t, to receive connecting-wires. The terminal t is preferably of somewhat more force than the others, as it is intended to perform the additional function of raising the hook-lever B and maintaining the same in its upper position when the receiver is removed t erefrom, and for this purpose this terminal is preferably constructed somewhat heavier than the others, preferably by increasing its width and thickness, as shown in Figs.

3 and 4. The spring-terminal t is also somewhat longer than the others and is extended upwardly at its forward end in such manner as to lie slightly above the plane of the other terminals, as shown in Figs. 1 and 2, where it receives an insulating-button on the under face of the switch-hook.

By reference to Figs. 3 and 4 it will be seen that the arrangement of the parts is such that the terminals are located approximately at one side of the center of the support or base and that the switch-hook lies approximately in the same vertical plane. The terminals are resilient and preferably are provided with suitable contact-points, as shown, it being apparent that by reason of the relative arrangement of the parts these contact-points have sliding motion on the surface of their cooperating springs, whereby the electrical connections are kept bright and free from deposits of all kinds.

The switch-hook B normally rests upon the contact '25 and depresses it against the contact 15, the weight of the telephone-receiver being sufficient to maintain this position while it is on the hook, whereby the terminals t and t are in electrical connection, and the terminals t and i which have a tendency to separate, are out of contact with each other and with the spring-terminal t, as shown in Figs. 1 and 5. When the receiver is removed from the hook, the spring trises from contact with the terminal t and contacts with the terminal 25 and in turn forces the terminals t and t together, as shown in Fig. 2.

The connections of the switch members in the circuit may be arranged for either an open or closed circuit system, and by way of illustration I have shown in Fig. 5 the proper connections from the terminals to the various instrumentalities of the apparatus, the reference-letters land Z representing the sides of a subscribers line, whereby when the telephone-receiver is on the hook and the parts occupy their normal relations the signal devices of the subscribers lines are included in the circuit, and when the receiver is removed and the instrument is employed for talking purposes the signal device is cut out and the telephone instruments are includedin the line, the switch members then assuming the position shown in Fig. 2.

The chief advantage of an organization of the mechanical parts as disclosed herein in this exempliiication of my invention is that all the parts are combined in a single unitary structure or grouped on a single support, whereby all the constituents of a telephoneswitch operated by the removal and replacernent of the telephone-receiver and all the terminals therefor may be bodily placed in and removed from the boX without disassembling any of the parts' Also a further advantage is obvious in an organization wherein the hook-raising spring-terminal is employed as the means to close the circuit through the other terminals and wherein this element is mounted in the same block with the other contacts.

Under some conditions of use it is found desirable to employ a supplemental spring to aid in raising the arm B, and when such construction is desired a suitable spring 8 may have one end seated in an opening .9 in the base A, and its other end bearing against a suitable pin or lug s on the arm, as shown.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a telephone-switch, in combination, a pivoted switch-hook, a spring-terminal engaging and tending to elevate the hook, a lower terminal with which the spring is in contact when the hook is depressed and upper terminals which are out of contact at such time, the said spring when the hook is released breaking contact with the lower terminal and elevating the hook sufficiently to cause the u per terminals to engage.

2. In a te ephone-switch, in combination, a base, a switch-hook pivoted thereto, a series of four resilient terminals on the base and insulated from each other, one of said terminals being a normally depressed switch-spring in electrical contact with the lower terminal and adapted to elevate the hook when the latter is unencumbered and to rise from contact with the lower terminal and force the upper a switch-hook pivoted to the standard, a block in the plate having lateral slits, a series of spring-contacts in the slits and having lateral ears embracing the block, one of the contacts extending beyond the others to support the hook and being normally in contact with another terminal and adapted to raise the hook when the latter is unencumbered and to electrically connect the other terminals with itself and with each other.

4. In a telephone-switch, in combination, a base having a seat and a standard, a switchhook pivoted to the standard, an insulatingblock in the seat and provided with kerls, a series of four resilient terminals in the kerfs,

one of the said terminals being normally depressed into contact with one of the other terminals and having an arm engaging the hook to raise the same when the receiver is removed and coincidently breaking contact with the terminal with which it is normally in contact and pressing the other two terminals into contact.

In witness whereof I aflix my signature in the presence of two witnesses.

ROBERT K. GUsTAFsoN, JOSIAH MoRoBERTs. 

